Indeed, wars often lead to the destruction of buildings that house records. People are often displaced in large numbers and they are separated from personal records.
Just last week, in one of Eddie's other posts, there was a reply that Union troops burned a southern courthouse during the Civil War creating a brick wall for everyone who has ancestors from that county.
And when one group tries to destroy another group, in addition to killing or displacing its members, extra efforts are taken to destroy their culture and history. In the same way, some Egyptian pharaohs smashed the reliefs of previous pharaohs who they wanted to "erase" from history.
As the Jews had their records destroyed by the Nazis, it presents a huge brick wall to their descendants the same as many African-Americans with the slavery wall.
Another group that saw their records smashed are the Russians. Prior to the communist revolution, most records were kept in the churches. The atheist Communists blew up the churches and burned records across the whole of the Soviet Union. Millions of records were burned and there is now a huge historical void in Eastern Europe.
What the Communists didn't burn was often burned by families themselves. Sadly, under Lenninist and Stalinst rule, genealogical records could earn you a bullet in a pit outside of town or get you sent to a sure death in the Siberian gulags. Finding records today is difficult, more so if the family had any ties to nobility. Records in Poland and Ukraine suffered similar fates with the added hurdle that many cities in those countries were totally destroyed in World War II. The Germans invaded going east, and a year or two later, the Soviets invaded heading west. In some cities, almost every building was destroyed.
War is bad for genealogy. Genocide, even worse.